JP2008236560A - Electric field communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric field communication apparatus in which communication quality of electric field communication is enhanced. <P>SOLUTION: A signal electrode 11A and a ground electrode 11B are disposed on the surface of a case 10. Thus, since the signal electrode 11A and the ground electrode 11B are not brought into contact with electronic components, such as a transmission circuit 21 disposed within the case 10, decrease in an electric field Ec induced in an electric field transport medium can be prevented. Furthermore, since the distance between the signal electrode 11A and the ground electrode 11B is kept, an electric field Ea from the signal electrode 11A to the ground electrode 11B is not increased, and decrease in the electric field Ec induced in the electric field transport medium can be prevented. Moreover, since tight adhesiveness between the signal electrode 11A and the electric field transport medium is improved, the electric field Ec induced in the electric field transport medium can be increased. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric field communication apparatus that transmits data by inducing an electric field in an electric field transmission medium.

  There has been proposed a technique of inducing an electric field in an electric field transmission medium such as a human body and performing data communication using the induced electric field (see Non-Patent Document 1).

  FIG. 13 is a schematic diagram for explaining a communication system that performs electric field communication using a human body as an electric field transmission medium. The communication system shown in the figure is a communication system that performs communication using an electric field induced by a user 401 between a transmission apparatus 201 and a reception apparatus 301.

When the transmission device 201 transmits data to the reception device 301, the transmission device 201 induces an electric field Ec in the user 401 by the signal electrode 201A. The receiving device 301 receives the data by detecting the electric field Ef induced by the user 401.
"RedTacton", [online], Nippon Telegraph and Telephone Corporation, [March 8, 2007 search], Internet <URL: http://www.redtacton.com/>

  However, even if the electric field Ec is induced in the user 401, there is an electric field Eb that returns from the user 401 to the ground electrode 201B and an electric field Ee that escapes from the user 401 to the ground. Therefore, the electric field Ef that reaches the receiving device 301 is The difference between the electric field Ec induced by the user, the electric field Eb, and the electric field Ee. There is also an electric field Ea that is directly input from the signal electrode 201A to the ground electrode 201B.

  In addition, when the electric field communication terminal is reduced in size and can be easily carried, a stress is applied to the casing of the electric field communication terminal, and the mounting component touches the electrode disposed inside the casing to induce the electric field Ec to the user 401. Or the distance between the signal electrode 201A and the ground electrode 201B is narrowed to increase the electric field Ea, thereby reducing the electric field Ec induced by the user.

  Furthermore, when the user 401 simultaneously contacts the signal electrode 201A and the ground electrode 201B, the electric field Eb returning from the user 401 to the ground electrode 201B increases, and the electric field Ef detected by the receiving device 301 decreases, thereby causing communication. There is a problem that quality deteriorates.

  This invention is made | formed in view of the above, The place made into the subject is to improve communication quality in an electric field communication terminal.

  An electric field communication apparatus according to a first aspect of the present invention is an electric field communication apparatus that induces an electric field based on information to be transmitted in an electric field transmission medium, and transmits and receives information using the electric field. Is electrically connected to the input / output terminal of the communication circuit, is electrically connected to the reference potential of the communication circuit, and is connected to the first electrode disposed on the outer surface of the housing. And a second electrode disposed on the outer surface of the housing so as to be insulated from the electrode.

  In the present invention, the first electrode and the second electrode are arranged on the outer surface of the housing containing the communication circuit, so that the electrode does not move even when stress is applied to the housing when carrying the communication device. Since no contact is made with electronic components such as a communication circuit and the distance between the electrodes is maintained, it is possible to prevent a decrease in output of the transmitter and a decrease in the amount of electric field detected as a reception signal. In addition, since the electrode is provided outside the housing, the adhesion between the electrode and the electric field transmission medium is improved, and the communication quality can be improved.

  An electric field communication apparatus according to a second aspect of the present invention is an electric field communication apparatus that induces an electric field based on information to be transmitted in an electric field transmission medium and transmits information using the electric field, and includes a transmission circuit and a transmission circuit A first electrode disposed on the outer surface of the casing, and electrically connected to a reference potential of the transmission circuit, the first electrode And a second electrode disposed on the outer surface of the casing.

  An electric field communication apparatus according to a third aspect of the present invention is an electric field communication apparatus that receives information induced in an electric field transmission medium, and includes a receiving circuit, a housing that houses the receiving circuit, an input terminal of the receiving circuit, A first electrode that is electrically connected and disposed on the outer surface of the housing, and is electrically connected to a reference potential of the receiving circuit, and is disposed on the outer surface of the housing so as to be insulated from the first electrode. And a second electrode.

  In the electric field communication device, the first electrode and the second electrode are disposed to face each other, and the second electrode is not formed at a position corresponding to a portion where the first electrode is disposed. Features.

  In the present invention, the second electrode disposed opposite to the first electrode is not formed at a position corresponding to the portion where the first electrode is disposed, so that the user holds the electric field communication device. In doing so, it is less likely to be in contact with the two electrodes at the same time, so that deterioration of communication quality can be suppressed.

  In the electric field communication device, the shape of the first electrode and the shape of the second electrode are different.

  In the present invention, since the first electrode and the second electrode have different shapes, even when the user contacts the two electrodes, the difference in the area in contact with the electrodes increases, so they cancel each other out. The electric field is reduced, and deterioration of communication quality can be suppressed.

  In the above electric field communication device, the area in contact with the electrode is that one of the first electrode and the second electrode has a plate shape, and the other electrode has a linear shape or a strip shape. It is desirable to increase the difference.

  In the above electric field communication device, the linear or strip electrode is deformable and does not physically contact the other electrode.

  In the present invention, by making the linear electrode deformable, it can be used as a strap for a key holder or the like.

  In the above electric field communication device, it is desirable that the linear or belt-like electrode has a length that does not contact the other electrode, in order not to physically contact the other electrode.

  The electric field communication device is characterized in that at least one metal layer is provided outside the at least one of the first electrode and the second electrode so as to be insulated from the electrode.

  In the present invention, by further including a metal layer such as a metal plate, the electric field coupling with the electric field transmission medium is improved and the electrode can be protected.

  In the electric field communication device, at least one outermost layer of the first electrode and the second electrode is covered with an insulating film.

  In this invention, it can prevent that an electric current flows into an electric field transmission medium by covering an electrode with an insulating film. In addition, metal allergy users can use it with peace of mind.

  In the electric field communication device, the corners of the first electrode and the second electrode are round.

  In the present invention, since the electric field between the first and second electrodes can be reduced by rounding the corners of the electrodes, the communication quality can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, communication quality can be improved in an electric field communication terminal.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Although each embodiment deals with a transmitter including a transmission circuit, it can be similarly applied to a receiver including a reception circuit, and also to a communication device including a transmission circuit and a reception circuit. The same can be applied.

[First Embodiment]
FIG. 1 is an exploded perspective view showing the configuration of the transmitter according to the first embodiment. The transmitter shown in the figure is an electric field communication transmitter that transmits data by inducing an electric field in an electric field transmission medium such as a human body. The electric field induced in the user by the transmitter reaches the receiver through the user and is coupled to the electro-optic crystal provided in the receiver. As a result, the optical properties of the electro-optic crystal change, and therefore, by irradiating the electro-optic crystal with laser light, the degree of change is detected to perform communication. Note that the transmitter shown in FIG. 1 can be used by being stored in a pocket or a bag by a user, for example.

  In the transmitter shown in FIG. 1, the signal electrode 11A and the ground electrode 11B are arranged on the opposing surfaces of the non-conductive housing 10 containing the transmission circuit 21 and the like, and the signal electrode 11A and the ground electrode 11B are respectively connected. The structure is covered with insulating films 12A and 12B. As shown in the figure, the casing 10 is a card case type rectangular parallelepiped, and the signal electrode 11A and the ground electrode 11B are arranged on the entire surface of the casing 10 having the largest area. For example, a copper plate having a thickness of about 0.5 mm is used for the signal electrode 11A and the ground electrode 11B. Thus, by arranging the signal electrode 11 </ b> A and the ground electrode 11 </ b> B on the outer surface of the housing 10, adhesion with the user can be improved.

  FIG. 2 is a side view showing the configuration of the transmitter shown in FIG. As shown in the figure, a transmitter circuit 21 is built in the casing 10 of the transmitter, and the signal electrode 11A disposed on the surface of the casing 10 is a signal disposed in the casing 10. The output terminal 22 is electrically connected. On the other hand, the ground electrode 11 </ b> B is electrically connected to the GND 23 of the transmission circuit 21. The surface of the housing 10 is bonded to the signal electrode 11A and the ground electrode 11B with a double-sided tape (not shown). Further, the signal electrode 11A and the ground electrode 11B are covered with the insulating films 12A and 12B, respectively, so that no current flows through the human body.

  As described above, the signal electrode 11A and the ground electrode 11B for inducing an electric field in the electric field transmission medium are arranged outside the casing 10, whereby the signal electrode 11A and the ground electrode 11B are arranged inside the casing 10. Therefore, the reduction of the electric field induced in the electric field transmission medium can be prevented. Further, by arranging the signal electrode 11A and the ground electrode 11B on the outer surface of the housing 10, the adhesion between the signal electrode 11A or the ground electrode 11B and the electric field transmission medium is improved. Even when the present embodiment is applied to a receiver in which the signal electrode 11A is connected to the input terminal of the receiving circuit, the signal component received by the signal electrode 11A is prevented from falling out to the ground electrode 11B. Similar to the device, the effect of improving the communication quality can be obtained.

  FIG. 3 is a side view showing the configuration of another transmitter according to the first embodiment. The transmitter shown in the figure is different from that shown in FIG. 2 in that the metal plates 13A and 13B and the insulating films 14A and 14B are provided. Other configurations are the same as those shown in FIG. The same components are denoted by the same reference numerals.

  The metal plates 13A and 13B shown in FIG. 3 are disposed on the surfaces of the insulating films 12A and 12B covering the signal electrode 11A and the ground electrode 11B, and are insulated from the signal electrode 11A and the ground electrode 11B. The metal plates 13A and 13B are further covered with insulating films 14A and 14B. Thus, by covering the signal electrode 11A and the ground electrode 11B with the metal plates 13A and 13B, the electric field coupling can be improved and the signal electrode 11A and the ground electrode 11B can be reinforced. A metal plated member may be used instead of the metal plates 13A and 13B. Further, not only the configuration in which the metal plates 13A and 13B are arranged on both the signal electrode 11A and the ground electrode 11B, but the metal plate 13B may be arranged only on one side as shown in FIG. Also good.

  Further, the corners of the copper plate forming the signal electrode 11A and the ground electrode 11B are rounded, and, for example, as shown in FIG. The electric field Ea toward the corner can be reduced.

  Therefore, according to the present embodiment, by arranging the signal electrode 11A and the ground electrode 11B on the surface of the casing 10, the signal electrode 11A and the ground electrode 11B such as the transmission circuit 21 disposed in the casing 10 are provided. Since the electronic component is not contacted, it is possible to prevent a reduction in the electric field Ec induced in the electric field transmission medium. Further, since the distance between the signal electrode 11A and the ground electrode 11B is maintained, the electric field Ea from the signal electrode 11A to the ground electrode 11B does not increase, and the decrease of the electric field Ec induced in the electric field transmission medium is prevented. Can do. Furthermore, since the adhesion between the signal electrode 11A and the electric field transmission medium is improved, the electric field Ec induced in the electric field transmission medium can be increased.

  According to the present embodiment, by rounding the corners of the signal electrode 11A and the ground electrode 11B, the electric field Ea from the signal electrode 11A to the ground electrode 11B can be reduced, so the electric field induced in the electric field transmission medium It becomes possible to increase Ec.

  According to the present embodiment, the signal electrode 11A and the ground electrode 11B are further covered with the metal plates 13A and 13B via the insulating films 12A and 12B, thereby improving the electric field coupling and the signal electrode 11A and the ground electrode 11B. Can be reinforced.

[Second Embodiment]
FIG. 6 is a plan view showing the electrodes of the transmitter in the second embodiment. 2A is a plan view of the signal electrode 41A connected to the signal output terminal 22 in the housing 10, and FIG. 2B is a diagram of the ground electrode 41B connected to the GND 23 in the housing 10. FIG. It is a top view. The signal electrode 11A and the ground electrode 11B shown in FIG. 1 of the first embodiment are arranged over almost the entire face of the housing 10, whereas the signal electrode 41A shown in FIG. The ground electrode 41 </ b> B is different in that the ground electrode 41 </ b> B is disposed only on a part of the opposing surface of the housing 10.

  As shown in FIG. 6, the signal electrode 41 </ b> A and the ground electrode 41 </ b> B have a structure in which a portion where the electrode is formed and a portion where the electrode is not formed are inverted to each other. As a result, when the transmitter is held by holding the surface on which the electrodes are arranged, the signal electrode 41A and the ground electrode 41B are less likely to come into contact at the same time, so that the electric field that cancels the electric field Ec induced by the user is reduced. Eb can be reduced.

  In addition, the ground electrode 41B disposed opposite to the signal electrode 41A is present in the portion corresponding to the signal electrode 41A, not only in the case where the portion where the electrode is formed and the portion where the electrode is not formed are inverted. Any structure may be used.

  In addition to the arrangement of the electrodes shown in FIG. 6, for example, as shown in FIGS. 7 (a) and 7 (b), one electrode is arranged on the lower half of the surface of the housing 10 and the other electrode is arranged on the upper side. It may be arranged in half. Of course, shapes other than those shown above may be used. The electrodes shown in FIGS. 6 and 7 are preferably arranged on the surface of the housing 10 as shown in the first embodiment, but are arranged inside the housing 10. Also good.

  Therefore, according to the present embodiment, since the signal electrode 41A and the ground electrode 41B are formed in a mutually inverted shape, when the user pinches the transmitter with a finger, the signal electrode 41A Since contact with the ground electrode 41B is reduced at the same time, communication quality can be prevented from deteriorating.

[Third Embodiment]
FIG. 8 is a plan view showing the configuration of the electrodes of the transmitter according to the third embodiment. FIG. 8A shows the state of the signal electrode 61A, and FIG. 8B shows the state of the ground electrode 61B. It shows a state. The signal electrode 61A and the ground electrode 61B shown in the figure are arranged on the surface of the transmitter casing 10 shown in FIG.

  As shown in FIG. 8, the signal electrode 61A is linear, the ground electrode 61B is rectangular, and the signal electrode 61A and the ground electrode 61B are asymmetric. By making the signal electrode 61A and the ground electrode 61B asymmetrical, even when the user simultaneously contacts the signal electrode 61A and the ground electrode 61B, the area of the portion that contacts the signal electrode 61A and the ground electrode 61B And the electric field canceled out decreases, so that it is possible to suppress a decrease in the electric field Ef reaching the receiver.

  The linear signal electrode 61A shown in FIG. 8A may be formed of a tape-like electrode as shown in FIG. The shape of the signal electrode 61A is not limited to the spiral shape as shown in FIG. 8A, and may be a comb shape, for example. 8A and 8B may be exchanged so that the shape of the signal electrode 61A remains rectangular and the ground electrode 61B has a linear or strip shape.

  FIG. 10 is an explanatory diagram illustrating a configuration of another transmitter according to the third embodiment. The transmitter shown in FIGS. 1 to 7 is a rectangular parallelepiped, but the transmitter shown in FIG. 10 is different in that it is a key holder type. A signal electrode 81A is arranged on the outer surface of the key holder casing 10, and a linear ground electrode 81B is arranged on the strap portion of the key holder and covered with an insulating member 82B. The periphery of the signal electrode 81A is covered with an insulating film 82A. The signal electrode 81A is electrically connected to the signal output terminal 22 of the transmission circuit 21, and the ground electrode 81B is electrically connected to GND of the transmission circuit 21.

  To prevent the signal electrode 81A and the ground electrode 81B from coming into physical contact with each other, the length of the ground electrode 81B is shortened, or the lower portion of the ground electrode 81B is covered with a hard plastic tube or the like. Is bent so that it does not come into contact with the signal electrode 81A.

  FIG. 11 is an explanatory diagram showing a configuration of still another transmitter according to the third embodiment. In the transmitter shown in FIG. 10, a metal plate 93A is arranged on the outer periphery of a signal electrode 91A with an insulating film 92A interposed therebetween, and the outermost periphery is covered with an insulating film 94A.

  FIG. 12 is an explanatory diagram showing a configuration of still another transmitter according to the third embodiment. The transmitter shown in FIG. 10 is obtained by further connecting a linear electrode 103A to the signal electrode 101A with respect to the transmitter shown in FIG. 10, and the electrode 103A is covered with an insulating member 104A. The electrode 103A is not short-circuited even if it contacts the signal electrode 101A, so there is no effect even if it is slightly bent.

  Therefore, according to the present embodiment, the signal electrode 61A and the ground electrode 61B have different shapes, so that the signal electrode 61A and the ground electrode can be provided even when the user simultaneously contacts the signal electrode 61A and the ground electrode 61B. Since the difference in the area of the portion in contact with 61B is large and the electric field canceled out decreases, it is possible to suppress a decrease in the electric field Ef reaching the receiver.

It is a disassembled perspective view which shows the structure of the transmitter in 1st Embodiment. It is a side view which shows the structure of the transmitter shown in FIG. It is a side view which shows the structure of another transmitter in 1st Embodiment. It is a side view which shows the structure of another transmitter in 1st Embodiment. It is a top view which shows the mode of the electrode with which another transmitter in 1st Embodiment is provided. It is a top view which shows the mode of the electrode with which the transmitter in 2nd Embodiment is provided. It is a top view which shows the mode of the electrode with which another transmitter in 2nd Embodiment is provided. It is a top view which shows the mode of the electrode with which the transmitter in 3rd Embodiment is provided. It is a top view which shows another example of the electrode shown to Fig.8 (a). It is explanatory drawing which shows the structure of another transmitter in 3rd Embodiment. It is explanatory drawing which shows the structure of another transmitter in 3rd Embodiment. It is explanatory drawing which shows the structure of another transmitter in 3rd Embodiment. It is a schematic diagram which shows the electric field model of an electric field communication system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Housing | casing 11A, 41A, 61A, 81A, 91A, 101A ... Signal electrode 11B, 41B, 61B, 81B ... Ground electrode 12A, 12B, 14A, 14B, 82A, 92A, 94A ... Insulating film 13A, 13B, 93A ... Metal plate 21 ... Transmission circuit 22 ... Signal output terminal 23 ... GND
201 ... Transmitting device 201A ... Signal electrode 201B ... Ground electrode 301 ... Receiving device 401 ... User

Claims (11)

An electric field communication device that induces an electric field based on information to be transmitted in an electric field transmission medium and transmits / receives information using the electric field,
A communication circuit;
A housing containing the communication circuit;
A first electrode electrically connected to an input / output terminal of the communication circuit and disposed on an outer surface of the housing;
A second electrode electrically connected to a reference potential of the communication circuit, insulated from the first electrode and disposed on an outer surface of the housing;
An electric field communication device comprising: An electric field communication device that induces an electric field based on information to be transmitted in an electric field transmission medium and transmits information using the electric field,
A transmission circuit;
A housing containing the transmission circuit;
A first electrode electrically connected to an output terminal of the transmission circuit and disposed on an outer surface of the housing;
A second electrode electrically connected to a reference potential of the transmission circuit, insulated from the first electrode and disposed on an outer surface of the housing;
An electric field communication device comprising: An electric field communication device for receiving information induced in an electric field transmission medium,
A receiving circuit;
A housing containing the receiving circuit;
A first electrode electrically connected to an input terminal of the receiving circuit and disposed on an outer surface of the housing;
A second electrode that is electrically connected to a reference potential of the receiving circuit, is disposed on an outer surface of the housing and is insulated from the first electrode;
An electric field communication device comprising:   The first electrode and the second electrode are disposed to face each other, and the second electrode is not formed at a position corresponding to a portion where the first electrode is disposed. The electric field communication apparatus according to any one of claims 1 to 3.   4. The electric field communication device according to claim 1, wherein a shape of the first electrode is different from a shape of the second electrode. 5.   6. The electric field communication according to claim 5, wherein one of the first electrode and the second electrode has a plate shape, and the other electrode has a linear shape or a strip shape. apparatus.   7. The electric field communication apparatus according to claim 6, wherein the linear or belt-like electrode is deformable and does not physically contact the other electrode.   8. The electric field communication device according to claim 7, wherein the linear or belt-like electrode has a length that does not contact the other electrode.   The electric field according to any one of claims 1 to 8, further comprising at least one metal layer insulated from the first electrode and the second electrode outside the at least one electrode. Communication device.   10. The electric field communication device according to claim 1, wherein an outermost layer of at least one of the first electrode and the second electrode is covered with an insulating film.   11. The electric field communication device according to claim 1, wherein corners of the first electrode and the second electrode are round.

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